GNUnet  0.11.x
Data Structures | Macros | Functions
gnsrecord_crypto.c File Reference

API for GNS record-related crypto. More...

#include "platform.h"
#include "gnunet_util_lib.h"
#include "gnunet_constants.h"
#include "gnunet_signatures.h"
#include "gnunet_arm_service.h"
#include "gnunet_gnsrecord_lib.h"
#include "gnunet_dnsparser_lib.h"
#include "gnunet_tun_lib.h"
Include dependency graph for gnsrecord_crypto.c:

Go to the source code of this file.

Data Structures

struct  KeyCacheLine
 Line in cache mapping private keys to public keys. More...
 

Macros

#define LOG(kind, ...)   GNUNET_log_from (kind, "gnsrecord", __VA_ARGS__)
 
#define CSIZE   64
 

Functions

static void derive_block_aes_key (struct GNUNET_CRYPTO_SymmetricInitializationVector *iv, struct GNUNET_CRYPTO_SymmetricSessionKey *skey, const char *label, const struct GNUNET_CRYPTO_EcdsaPublicKey *pub)
 Derive session key and iv from label and public key. More...
 
struct GNUNET_GNSRECORD_Block * block_create (const struct GNUNET_CRYPTO_EcdsaPrivateKey *key, const struct GNUNET_CRYPTO_EcdsaPublicKey *pkey, struct GNUNET_TIME_Absolute expire, const char *label, const struct GNUNET_GNSRECORD_Data *rd, unsigned int rd_count)
 Sign name and records. More...
 
struct GNUNET_GNSRECORD_Block * GNUNET_GNSRECORD_block_create (const struct GNUNET_CRYPTO_EcdsaPrivateKey *key, struct GNUNET_TIME_Absolute expire, const char *label, const struct GNUNET_GNSRECORD_Data *rd, unsigned int rd_count)
 Sign name and records. More...
 
struct GNUNET_GNSRECORD_Block * GNUNET_GNSRECORD_block_create2 (const struct GNUNET_CRYPTO_EcdsaPrivateKey *key, struct GNUNET_TIME_Absolute expire, const char *label, const struct GNUNET_GNSRECORD_Data *rd, unsigned int rd_count)
 Sign name and records, cache derived public key (also keeps the private key in static memory, so do not use this function if keeping the private key in the process'es RAM is a major issue). More...
 
int GNUNET_GNSRECORD_block_verify (const struct GNUNET_GNSRECORD_Block *block)
 Check if a signature is valid. More...
 
int GNUNET_GNSRECORD_block_decrypt (const struct GNUNET_GNSRECORD_Block *block, const struct GNUNET_CRYPTO_EcdsaPublicKey *zone_key, const char *label, GNUNET_GNSRECORD_RecordCallback proc, void *proc_cls)
 Decrypt block. More...
 
void GNUNET_GNSRECORD_query_from_private_key (const struct GNUNET_CRYPTO_EcdsaPrivateKey *zone, const char *label, struct GNUNET_HashCode *query)
 Calculate the DHT query for a given label in a given zone. More...
 
void GNUNET_GNSRECORD_query_from_public_key (const struct GNUNET_CRYPTO_EcdsaPublicKey *pub, const char *label, struct GNUNET_HashCode *query)
 Calculate the DHT query for a given label in a given zone. More...
 

Detailed Description

API for GNS record-related crypto.

Author
Martin Schanzenbach
Matthias Wachs
Christian Grothoff

Definition in file gnsrecord_crypto.c.

Macro Definition Documentation

◆ LOG

#define LOG (   kind,
  ... 
)    GNUNET_log_from (kind, "gnsrecord", __VA_ARGS__)

Definition at line 38 of file gnsrecord_crypto.c.

◆ CSIZE

#define CSIZE   64

Referenced by GNUNET_GNSRECORD_block_create2().

Function Documentation

◆ derive_block_aes_key()

static void derive_block_aes_key ( struct GNUNET_CRYPTO_SymmetricInitializationVector *  iv,
struct GNUNET_CRYPTO_SymmetricSessionKey *  skey,
const char *  label,
const struct GNUNET_CRYPTO_EcdsaPublicKey *  pub 
)
static

Derive session key and iv from label and public key.

Parameters
ivinitialization vector to initialize
skeysession key to initialize
labellabel to use for KDF
pubpublic key to use for KDF

Next time we break protocol (v12) we harmonize the KDF usage in GNS: We use the strings above as salt and the public key as IKM similar to how derive_h is done in crypto_ecc.c.

Definition at line 50 of file gnsrecord_crypto.c.

References GNUNET_CRYPTO_kdf().

Referenced by block_create(), and GNUNET_GNSRECORD_block_decrypt().

54 {
55  static const char ctx_key[] = "gns-aes-ctx-key";
56  static const char ctx_iv[] = "gns-aes-ctx-iv";
62 #ifdef LSD001
63  GNUNET_CRYPTO_kdf (skey, sizeof(struct GNUNET_CRYPTO_SymmetricSessionKey),
64  ctx_key, strlen (ctx_key),
65  pub, sizeof(struct GNUNET_CRYPTO_EcdsaPublicKey),
66  label, strlen (label),
67  NULL, 0);
68  GNUNET_CRYPTO_kdf (iv, sizeof(struct
69  GNUNET_CRYPTO_SymmetricInitializationVector),
70  ctx_iv, strlen (ctx_iv),
71  pub, sizeof(struct GNUNET_CRYPTO_EcdsaPublicKey),
72  label, strlen (label),
73  NULL, 0);
74 #else
75  GNUNET_CRYPTO_kdf (skey, sizeof(struct GNUNET_CRYPTO_SymmetricSessionKey),
76  pub, sizeof(struct GNUNET_CRYPTO_EcdsaPublicKey),
77  label, strlen (label),
78  ctx_key, strlen (ctx_key),
79  NULL, 0);
80  GNUNET_CRYPTO_kdf (iv, sizeof(struct
81  GNUNET_CRYPTO_SymmetricInitializationVector),
82  pub, sizeof(struct GNUNET_CRYPTO_EcdsaPublicKey),
83  label, strlen (label),
84  ctx_iv, strlen (ctx_iv),
85  NULL, 0);
86 #endif
87 }
GNUNET_CRYPTO_SymmetricSessionKey
type for session keys
Definition: gnunet_crypto_lib.h:277
GNUNET_CRYPTO_EcdsaPublicKey
Public ECC key (always for Curve25519) encoded in a format suitable for network transmission and ECDS...
Definition: gnunet_crypto_lib.h:203
GNUNET_CRYPTO_SymmetricInitializationVector
IV for sym cipher.
Definition: gnunet_crypto_lib.h:298
GNUNET_CRYPTO_kdf
int GNUNET_CRYPTO_kdf(void *result, size_t out_len, const void *xts, size_t xts_len, const void *skm, size_t skm_len,...)
Derive key.
Definition: crypto_kdf.c:89
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◆ block_create()

struct GNUNET_GNSRECORD_Block* block_create ( const struct GNUNET_CRYPTO_EcdsaPrivateKey *  key,
const struct GNUNET_CRYPTO_EcdsaPublicKey *  pkey,
struct GNUNET_TIME_Absolute  expire,
const char *  label,
const struct GNUNET_GNSRECORD_Data *  rd,
unsigned int  rd_count 
)

Sign name and records.

Parameters
keythe private key
pkeyassociated public key
expireblock expiration
labelthe name for the records
rdrecord data
rd_countnumber of records
Returns
NULL on error (block too large)

Definition at line 102 of file gnsrecord_crypto.c.

References GNUNET_TIME_Absolute::abs_value_us, derive_block_aes_key(), GNUNET_GNSRECORD_Block::derived_key, GNUNET_GNSRECORD_Data::expiration_time, GNUNET_GNSRECORD_Block::expiration_time, GNUNET_GNSRECORD_Data::flags, GNUNET_assert, GNUNET_break, GNUNET_CRYPTO_ecdsa_key_get_public(), GNUNET_CRYPTO_ecdsa_private_key_derive(), GNUNET_CRYPTO_ecdsa_sign(), GNUNET_CRYPTO_symmetric_encrypt(), GNUNET_free, GNUNET_GNSRECORD_MAX_BLOCK_SIZE, GNUNET_GNSRECORD_records_get_size(), GNUNET_GNSRECORD_records_serialize(), GNUNET_GNSRECORD_RF_RELATIVE_EXPIRATION, GNUNET_malloc, GNUNET_memcpy, GNUNET_OK, GNUNET_SIGNATURE_PURPOSE_GNS_RECORD_SIGN, GNUNET_TIME_absolute_add(), GNUNET_TIME_absolute_get(), GNUNET_TIME_absolute_hton(), payload, GNUNET_CRYPTO_EccSignaturePurpose::purpose, GNUNET_GNSRECORD_Block::purpose, GNUNET_TIME_Relative::rel_value_us, GNUNET_GNSRECORD_Block::signature, and GNUNET_CRYPTO_EccSignaturePurpose::size.

Referenced by GNUNET_GNSRECORD_block_create(), and GNUNET_GNSRECORD_block_create2().

108 {
109  ssize_t payload_len = GNUNET_GNSRECORD_records_get_size (rd_count,
110  rd);
111  struct GNUNET_GNSRECORD_Block *block;
112  struct GNUNET_CRYPTO_EcdsaPrivateKey *dkey;
113  struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
114  struct GNUNET_CRYPTO_SymmetricSessionKey skey;
115  struct GNUNET_GNSRECORD_Data rdc[GNUNET_NZL (rd_count)];
116  uint32_t rd_count_nbo;
117  struct GNUNET_TIME_Absolute now;
118 
119  if (payload_len < 0)
120  {
121  GNUNET_break (0);
122  return NULL;
123  }
124  if (payload_len > GNUNET_GNSRECORD_MAX_BLOCK_SIZE)
125  {
126  GNUNET_break (0);
127  return NULL;
128  }
129  /* convert relative to absolute times */
130  now = GNUNET_TIME_absolute_get ();
131  for (unsigned int i = 0; i < rd_count; i++)
132  {
133  rdc[i] = rd[i];
134  if (0 != (rd[i].flags & GNUNET_GNSRECORD_RF_RELATIVE_EXPIRATION))
135  {
136  struct GNUNET_TIME_Relative t;
137 
138  /* encrypted blocks must never have relative expiration times, convert! */
139  rdc[i].flags &= ~GNUNET_GNSRECORD_RF_RELATIVE_EXPIRATION;
140  t.rel_value_us = rdc[i].expiration_time;
141  rdc[i].expiration_time = GNUNET_TIME_absolute_add (now, t).abs_value_us;
142  }
143  }
144  /* serialize */
145  rd_count_nbo = htonl (rd_count);
146  {
147  char payload[sizeof(uint32_t) + payload_len];
148 
149  GNUNET_memcpy (payload,
150  &rd_count_nbo,
151  sizeof(uint32_t));
152  GNUNET_assert (payload_len ==
153  GNUNET_GNSRECORD_records_serialize (rd_count,
154  rdc,
155  payload_len,
156  &payload[sizeof(uint32_t)
157  ]));
158  block = GNUNET_malloc (sizeof(struct GNUNET_GNSRECORD_Block)
159  + sizeof(uint32_t)
160  + payload_len);
161  block->purpose.size = htonl (sizeof(uint32_t)
162  + payload_len
163  + sizeof(struct
164  GNUNET_CRYPTO_EccSignaturePurpose)
165  + sizeof(struct GNUNET_TIME_AbsoluteNBO));
166  block->purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_GNS_RECORD_SIGN);
167  block->expiration_time = GNUNET_TIME_absolute_hton (expire);
168  /* encrypt and sign */
169  dkey = GNUNET_CRYPTO_ecdsa_private_key_derive (key,
170  label,
171  "gns");
172  GNUNET_CRYPTO_ecdsa_key_get_public (dkey,
173  &block->derived_key);
174  derive_block_aes_key (&iv,
175  &skey,
176  label,
177  pkey);
178  GNUNET_break (payload_len + sizeof(uint32_t) ==
179  GNUNET_CRYPTO_symmetric_encrypt (payload,
180  payload_len
181  + sizeof(uint32_t),
182  &skey,
183  &iv,
184  &block[1]));
185  }
186  if (GNUNET_OK !=
187  GNUNET_CRYPTO_ecdsa_sign (dkey,
188  &block->purpose,
189  &block->signature))
190  {
191  GNUNET_break (0);
192  GNUNET_free (dkey);
193  GNUNET_free (block);
194  return NULL;
195  }
196  GNUNET_free (dkey);
197  return block;
198 }
GNUNET_GNSRECORD_Block::expiration_time
struct GNUNET_TIME_AbsoluteNBO expiration_time
Expiration time of the block.
Definition: gnunet_gnsrecord_lib.h:278
GNUNET_GNSRECORD_Data
A GNS record.
Definition: gnunet_gnsrecord_lib.h:195
GNUNET_GNSRECORD_records_get_size
GNUNET_NETWORK_STRUCT_END ssize_t GNUNET_GNSRECORD_records_get_size(unsigned int rd_count, const struct GNUNET_GNSRECORD_Data *rd)
Calculate how many bytes we will need to serialize the given records.
Definition: gnsrecord_serialization.c:88
GNUNET_CRYPTO_EccSignaturePurpose::purpose
uint32_t purpose
What does this signature vouch for? This must contain a GNUNET_SIGNATURE_PURPOSE_XXX constant (from g...
Definition: gnunet_crypto_lib.h:145
GNUNET_GNSRECORD_records_serialize
ssize_t GNUNET_GNSRECORD_records_serialize(unsigned int rd_count, const struct GNUNET_GNSRECORD_Data *rd, size_t dest_size, char *dest)
Serialize the given records to the given destination buffer.
Definition: gnsrecord_serialization.c:154
GNUNET_assert
#define GNUNET_assert(cond)
Use this for fatal errors that cannot be handled.
Definition: gnunet_common.h:829
GNUNET_GNSRECORD_MAX_BLOCK_SIZE
#define GNUNET_GNSRECORD_MAX_BLOCK_SIZE
Maximum size of a value that can be stored in a GNS block.
Definition: gnunet_gnsrecord_lib.h:47
GNUNET_memcpy
#define GNUNET_memcpy(dst, src, n)
Call memcpy() but check for n being 0 first.
Definition: gnunet_common.h:1101
GNUNET_OK
#define GNUNET_OK
Named constants for return values.
Definition: gnunet_common.h:75
GNUNET_TIME_absolute_add
struct GNUNET_TIME_Absolute GNUNET_TIME_absolute_add(struct GNUNET_TIME_Absolute start, struct GNUNET_TIME_Relative duration)
Add a given relative duration to the given start time.
Definition: time.c:395
GNUNET_CRYPTO_EcdsaPrivateKey
Private ECC key encoded for transmission.
Definition: gnunet_crypto_lib.h:253
t
static struct GNUNET_SCHEDULER_Task * t
Main task.
Definition: gnunet-zonewalk.c:121
GNUNET_GNSRECORD_Block
Information we have in an encrypted block with record data (i.e.
Definition: gnunet_gnsrecord_lib.h:257
GNUNET_TIME_AbsoluteNBO
Time for absolute time used by GNUnet, in microseconds and in network byte order. ...
Definition: gnunet_time_lib.h:85
GNUNET_TIME_Absolute::abs_value_us
uint64_t abs_value_us
The actual value.
Definition: gnunet_time_lib.h:53
GNUNET_break
#define GNUNET_break(cond)
Use this for internal assertion violations that are not fatal (can be handled) but should not occur...
Definition: gnunet_common.h:888
GNUNET_CRYPTO_EccSignaturePurpose
header of what an ECC signature signs this must be followed by "size - 8" bytes of the actual signed ...
Definition: gnunet_crypto_lib.h:130
GNUNET_CRYPTO_ecdsa_sign
int GNUNET_CRYPTO_ecdsa_sign(const struct GNUNET_CRYPTO_EcdsaPrivateKey *priv, const struct GNUNET_CRYPTO_EccSignaturePurpose *purpose, struct GNUNET_CRYPTO_EcdsaSignature *sig)
ECDSA Sign a given block.
Definition: crypto_ecc.c:928
GNUNET_CRYPTO_SymmetricSessionKey
type for session keys
Definition: gnunet_crypto_lib.h:277
GNUNET_CRYPTO_symmetric_encrypt
ssize_t GNUNET_CRYPTO_symmetric_encrypt(const void *block, size_t size, const struct GNUNET_CRYPTO_SymmetricSessionKey *sessionkey, const struct GNUNET_CRYPTO_SymmetricInitializationVector *iv, void *result)
Encrypt a block using a symmetric sessionkey.
Definition: crypto_symmetric.c:130
GNUNET_CRYPTO_EccSignaturePurpose::size
uint32_t size
How many bytes does this signature sign? (including this purpose header); in network byte order (!)...
Definition: gnunet_crypto_lib.h:137
GNUNET_TIME_absolute_get
struct GNUNET_TIME_Absolute GNUNET_TIME_absolute_get(void)
Get the current time.
Definition: time.c:118
GNUNET_CRYPTO_ecdsa_key_get_public
void GNUNET_CRYPTO_ecdsa_key_get_public(const struct GNUNET_CRYPTO_EcdsaPrivateKey *priv, struct GNUNET_CRYPTO_EcdsaPublicKey *pub)
Extract the public key for the given private key.
Definition: crypto_ecc.c:239
payload
static unsigned long long payload
How much data are we currently storing in the database?
Definition: gnunet-service-datastore.c:183
derive_block_aes_key
static void derive_block_aes_key(struct GNUNET_CRYPTO_SymmetricInitializationVector *iv, struct GNUNET_CRYPTO_SymmetricSessionKey *skey, const char *label, const struct GNUNET_CRYPTO_EcdsaPublicKey *pub)
Derive session key and iv from label and public key.
Definition: gnsrecord_crypto.c:50
GNUNET_NZL
#define GNUNET_NZL(l)
Macro used to avoid using 0 for the length of a variable-size array (Non-Zero-Length).
Definition: gnunet_common.h:178
GNUNET_GNSRECORD_Block::signature
struct GNUNET_CRYPTO_EcdsaSignature signature
Signature of the block.
Definition: gnunet_gnsrecord_lib.h:262
GNUNET_SIGNATURE_PURPOSE_GNS_RECORD_SIGN
#define GNUNET_SIGNATURE_PURPOSE_GNS_RECORD_SIGN
Signature of a gnunet naming system record block.
Definition: gnunet_signatures.h:125
GNUNET_TIME_Absolute
Time for absolute times used by GNUnet, in microseconds.
Definition: gnunet_time_lib.h:48
GNUNET_GNSRECORD_RF_RELATIVE_EXPIRATION
This flag is currently unused; former RF_PENDING flag.
Definition: gnunet_gnsrecord_lib.h:169
GNUNET_CRYPTO_SymmetricInitializationVector
IV for sym cipher.
Definition: gnunet_crypto_lib.h:298
GNUNET_CRYPTO_ecdsa_private_key_derive
struct GNUNET_CRYPTO_EcdsaPrivateKey * GNUNET_CRYPTO_ecdsa_private_key_derive(const struct GNUNET_CRYPTO_EcdsaPrivateKey *priv, const char *label, const char *context)
Derive a private key from a given private key and a label.
Definition: crypto_ecc.c:1293
GNUNET_GNSRECORD_Block::purpose
struct GNUNET_CRYPTO_EccSignaturePurpose purpose
Number of bytes signed; also specifies the number of bytes of encrypted data that follow...
Definition: gnunet_gnsrecord_lib.h:273
GNUNET_TIME_absolute_hton
struct GNUNET_TIME_AbsoluteNBO GNUNET_TIME_absolute_hton(struct GNUNET_TIME_Absolute a)
Convert absolute time to network byte order.
Definition: time.c:657
GNUNET_GNSRECORD_Block::derived_key
struct GNUNET_CRYPTO_EcdsaPublicKey derived_key
Derived key used for signing; hash of this is the query.
Definition: gnunet_gnsrecord_lib.h:267
GNUNET_malloc
#define GNUNET_malloc(size)
Wrapper around malloc.
Definition: gnunet_common.h:1156
GNUNET_free
#define GNUNET_free(ptr)
Wrapper around free.
Definition: gnunet_common.h:1200
GNUNET_TIME_Relative
Time for relative time used by GNUnet, in microseconds.
Definition: gnunet_time_lib.h:60
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